There are many different factors which can limit the durability of articles besides normal wear during use. Color fading, surface abrasion, and soiling, for example, can sufficiently diminish the aesthetics of an article so that it ought to be replaced. Some items such as photographs and works of art cannot be replaced when such damage has been wrought on them. In the past, clear films of synthetic polymers containing epoxy-terminated silanes have been used to protect certain items, including color photographs, against degradation.
U.S. Pat. No. 4,049,861 discloses abrasion resistant coatings based upon the polymerization of epoxy-terminated silanes. A high degree of abrasion resistance is provided by that technology in combination with polyepoxide resins.
U.S. Pat. No. 4,156,046 discloses an abrasion resistant, bloom resistant coating for use on substrates which are susceptible to damage from ultraviolet radiation, abrasion, and/or soiling. The abrasion resistant ultraviolet radiation protective coatings of U.S. Pat. No. 4,156,046 are highly effective, but tend to be subject to surface crazing when contacted with water. It is surprising that such water sensitivity exists in a coating that is resistant even to very strong solvents, and it would be desirable to eliminate the water-sensitivity. U.S. Pat. No. 4,293,606 discloses low friction, abrasion resistant coatings for transparent film, particularly motion picture film. Siloxyl containing carbinols and fine particles are used to reduce the frictional properties of the coatings. A wide range of aliphatic and aromatic epoxy comonomers are disclosed as copolymerizable with the epoxy-silane main component.
U.S. Pat. No. 4,497,861 discloses the use of 15 to 30% by weight of limonene monoxide with at least 60% by weight of epoxy-terminated silane to produce a transparent abrasion resistant coating with reduced water sensitivity. Limonene monoxide has a strong offensive odor which requires significant ventilation in the workplace.
These patents generally teach the use of polyepoxy and aromatic epoxy comonomers which have been found to generate highly unfavorable odors in the workplace. U.S. Pat. No. 4,293,606 generally includes aliphatic epoxy resin comonomers in its disclosure but does not differentiate amongst them for their properties.